Method of making etched glassware



June 2, 1936. R. L. WOOLES 2,043,025

METHOD OF MAKING ETCHED GLASSWARE Filed July 28, 1933 HIIIIIH INVENTOR.

ma-MW ATTORNEYS.

Patented June 2, 1936 METHOD OF MAKING ETCHED GLASSWARE Ronald L.Wooles, Newark, Ohio, assignor to A. H.

Heisey & Company, Newark, Ohio, a corporation of Ohio Application July28, 1933, Serial No. 682,658

3 Claims.

My invention relates to etched glassware and method of making the same.It has to do particularly with the production of etched designs uponglassware in the formation of the outline 5 for the design by theetching process itself rather than by molding, though it is notnecessarily limited thereto.

In the prior art, various methods have been utilized for etchingarticles of glassware. One common method is to apply beeswax coating tothe entire article and then remove certain parts of the beeswax by meansof a mechanically actuated needle which inscribes a predetermined designand which leaves the glass at the point of removal subject to attack ofthe etching acid upon dipping of the article therein. This method issubject to rather severe limitations because of the mechanicaldifficulties in the production of any great number of different designsand because of the stereotyped nature of the designs that can beproduced thereby.

Another prior art method that has been used to a considerable extentconsists in the photographing of a given design upon a sensitized metalplate, the etching of this metal plate to develop the design in reliefthereon and the subsequent use of this plate for the making ofacidresist patterns. These patterns are produced by coating the metalplate with the acid-resist which is generally black and then applying astrip or sheet of paper to the coated plate so that the paper will berather heavily coated with the black acid-resist and the design will beformed in the coating of acid-resist. The pattern is then applied to thearticle of glassware and the material is such that the paper may bemoistened and removed so as to leave the acid-resist on the glasswarewith the preselected design appearing therein. The glass article is thencovered fully with the acid-resist, with the exception of the designarea.

At this stage in the operation, the article is ordinarily dipped into a60% solution of hydrofluoric acid mixed with from two and one-half tothree parts of water. The usual period of immersion is from fifteen totwenty minutes. The only type of etching ordinarily considered feasiblewith this process in the past has been what may be termed a line etchingwherein a design 00 is produced in the glassware by a series ofrelatively thin lines along which this comparatively weak acid hasoperated to etch the glass. With this type of etching, the acid, beingmore or less concentrated along sharply defined narrow lines, produceswhat appears under the microscope to be a series'of definite channelswith comparatively abrupt sides. To the normal vision, the lines whichgo to make up such an etching appear quite similar to those lines Whichresult from the process wherein the design is inscribed upon the beeswaxcoated by the mechanically actuated needle.

Another prior art process commonly used inv etching glass is known asmatt etching. In performing this process, the glass is usually subjectedto a weak acid for a short length of time in order to produce the mattsurface on the glass. This matt surface comprises a surface which isfrosted in nature and which is of substantially uniform characteristicsthroughout its area. This frosted surface usually does not possessa'very high degree of transparency and the entire frosted area hassubstantially the same degree of trans- 'parency.

Some eifort has been made to produce what may be termed a silhouetteetching by forming a selected design in an article of glassware duringthe molding thereof and then covering this design with an etching acidto give it a more or less frosted appearance. Generally, in this method,it is customary to provide the base or a wall of the mold with a designin relief so that the pressing of the glass in the mold reproduces anindented design in the glass article. Then, this indented design isordinarily subjected to a weak acid for a moment or two so that thissurface .is given a slightly frosted and comparatively glossyappearance. Frequently, the area surrounding the design must be groundand polished to complete the article.

My method contemplates the making of a silhouette etching upon glasswareand the production of this silhouette without the use of a moldingprocess. Instead of molding the design into the article, the exterioroutline of the design is delineated by the interior outline of anacid-resisting material which is preferably black and which entirelycovers the article with the excep tion of the area or areas which are tobe etched. With the article so covered by the acid-resisting material,it is dipped into an acid of such a strength and for such a period ofapplication as to effect an etching of the design area and to therebyproduce a silhouette design upon the glass which is rough and glassy inits nature, which is of uneven depth throughout and which possessesvarious degrees of transparency at various points in its area, as willbe more fully explained later.

Samples of articles produced by my method with a line etching producedthereon by a prior art process.

Figure 4 is a magnified view of the surface indicated by the circle inFigure 1 illustrating the nature of the etched surface produced by mymethod.

Figure 5 is a magnified view of the surface indicated by the circle inFigure 3 illustrating the nature of the etched surface produced by thelineetching method of the prior art.

Figure 6 is a magnified view of a matt surface produced by a well knownprior art matt-etching process.

Describing my process more specifically, it consists in the initialproduction of a design photographically upon a sensitized metal plate,followed by the etching of the design upon the plate by any suitablemethod and then by the removal of the sensitized surface and the use ofthe etched plate for the making of transfer sheets wherein the design isreproduced in an acid-resisting material. To accomplish this the etchedmetal plate is coated with the black acid-resisting material in fluidform and a thin paper sheet is applied thereto, with the result that thedesign in black and white is imprinted upon the paper with the whiteportions thereof representing the design and the black portions thereofrepresenting the surrounding acid-resisting material.

The sheet thus printed is removed and wrapped about the glass articleupon which the design is to be reproduced, with the acid-resistingmaterial in contact with the glass. Then, the paper is washed off by asolution which will leave the acid-resisting material upon the glasswith a design represented therein by uncovered portions of the glasssurface. It is then desirable to apply such additional amounts ofacid-resisting material to the glass article that it will be completelyprotected from the acid at all points with the exception of the designarea.

The article which has thus been protected is, preferably, dipped into asolution made up of 2 parts of water and 1 part of 80% hydrofluoricacid. It is held in this solution for a period ranging from 45 to 60minutes.

Apparently, due to the fact that the designs which I use are silhouettesand to the fact that a comparatively strong acid is used for acomparatively long time, the nature of the etched surface of the glassis quite different in appearance from prior art etched glass surfaceswith which I am familiar. It is markedly different from those articlesof etched glassware in which the design is produced by a plurality oflines. It is also markedly different from those etched surfaces producedby the well known matt-etching process.

In Figure 4, I have illustrated a microscopic view of an etched surfaceproduced by my process. In Figure 5, I have illustrated a microscopicview of a line etching produced by the prior art method, and in Figure6, I have illustrated a microscopic view of a matt-etched surfaceproduced by a well known matt-etching process. A comparison of thesethree figures will clearly bring out the differences between a surfaceproduced by my process and a surface produced by either of the two priorart processes.

As clearly shown in Figure 4, the surface produced by my method isprovided throughout its area with a multiplicity of ridges interspersedwith valleys or lowered portions. The surface produced by the prior artline-etching method illustrated in Figure 5 embodies comparatively wide,fiat areas with distinct and definite channels or canals which areclearly delineated therein. The matt-etched surface illustrated inFigure 6 is merely frosted in nature and of uniform depth, being ofsubstantially uniform characteristics throughout its area. The highportions of the surface produced by my process are substantially frostedin nature, though more rough than the usual matt etching, while thelower portions are clearer and possess a greater degree of transparencyand the very deepest portions are substantially clear in nature andpossess a very high degree of transparency. The prior art matt surfacedoes not possess a very high degree of transparency, but the entire areathereof is frosted, being comparatively smooth and having substantiallythe same degree of transparency throughout its area.

In addition to the differences appearing under the microscope, markeddifferences also appear from a comparative examination of the threesurfaces by normal vision. Thus, a glass surface etched in accordancewith my invention shows a rough, glassy area which is devoid of linesbut which is more heavily frosted in some places than in others and, incertain portions, is substantially clear. This gives the surface apleasing appearance with various degrees of transparency throughoutvarious portions of the area thereof. The deeper portions possess thegreater degree of transparency and usually occur toward the center ofthe design. On the other hand, the glass surface etched in accordancewith the said prior art line-etching method shows a multiplicity ofdistinct lineal depressions which are so related to each other as toproduce the complete design. A matt surface produced by a prior artprocess also differs greatly in appearance from a surface produced by myprocess. Such a matt surface has a uniform appearance throughout itsarea which is frosted in nature and has the same degree of transparencythroughout.

A comparison of the three surfaces by a sense of touch also shows thatthe prior art etched surfaces are clearly different in nature from anetched surface produced by my process. By touching a surface produced inaccordance with my process, it will be apparent that the surface is ofirregular depth, with apparent tendency toward deeper etching in thecenter of any silhouetted figure and with the thicker and more heavilyfrosted areas adjacent the edges of the figure. In fact, with some largesilhouette figures, portions at the center thereof are sometimes entirely devoid of any frosting. With an article etched by the prior artline-etching process, the etching seems to be more or less uniformthroughout. This is, also, true of a surface produced by thematt-etching process. Such a surface presents uniform characteristicsthroughout its area which may be readily noticed by the sense of touch.

The net result of these differences which arise from the production ofsilhouette etchings upon glassware by my process is that the silhouettedfigures, though beneath the surrounding surface of the glass article,have an appearance of being in relief. Moreover, the very lack ofuniformity of elevation of the etched surfaces and, consequently, thelack of uniformity of transparency, presents a pleasing variety ineffect not hitherto attainable by any process with which I am familiar.

As previously stated, the novel surface which I obtain by my process isapparently due to the fact that the designs are silhouettes having wideareas and that I use a. comparatively strong acid for a comparativelylong time. Apparently, after the article is placed in the acid, itreacts with the glass to produce insoluble salts which cling to thesurface. These salts apparently do not deposit uniformly throughout thearea of the uncovered portion of the glass which forms the silhouettefigure. Consequently, the acid does not eat into the glass for a uniformdepth throughout the design but will more readily eat into the glasswhere there is only a slight deposit of the insoluble salts or where theglass is entirely devoid of the salts. As previously stated, the acidusually eats more deeply into the glass toward the center of thesilhouette figure and this is, apparently, due to the fact that theinsoluble salts are more readily washed off at the center of thesilhouette figure.

It is also possible to apply my process for the production of designsupon glass articles merely by painting the acid resist directly upon thearticle by means of a brush, leaving the unpainted surface free forsubjection to the'etching acid, with the design determined by thepainting operation. After this step has been performed, it is merelynecessary to dip the article into the hydrofluoric solution of thestrength indicated and for the period of time indicated.

It will be seen from this that various other acid solutions may beutilized in the performance of my method for producing articles of thetype indicated. Thus, it is probable that the hydrofluoric solution maybe supplemented by a fluoride such as commonly used in matt etching. Forexample, potassium or ammonium fluoride may be used for this purpose.The periods of dipping and consequent subjection of glass to the acidmay vary with the particular solution used for performing the etchingoperation. Likewise, a somewhat weaker solution of acid may be used fora longer period of time or a stronger solution of the acid may be usedfor a shorter period of time in obtaining the desired resultsby myprocess.

It will be seen from the description set forth above that I haveprovided a novel method of making etched articles of glassware whichpermits the formation of designs and figures materially different incharacter from the stereotyped designs commonly made by the productionof a multiplicity of depressed lines which, by their particulararrangement, produce the design sought and which are, also, noticeablydifferent in character from prior art matt etchings. The method which Iutilize for producing silhouette etchings in glassware dispenses withthe necessity 5 of producing the silhouette figure to be etched bymolding it into the glassware and then applying the acid to thedepressed surface so formed. This prior art method involves additionaland costly steps of operation, such as the preparation of a mold withprotuberances thereon and which frequently necessitates the grinding andpolishing of the surface surrounding the etched area after the etchingoperation has been completed, none of these steps being necessary in theperformance of my method.

It will also be seen that I have produced a novel article of glassware.As distinguished from the prior art, it may be termed a glass articleembodying a design produced thereon by etching and having the silhouetteetched to different depths at different areas thereof and, consequently,having portions thereof of varying degrees of transparency.

In this specification, I have described my process as being used forproducing designs on transparent glass. Obviously, it might also be usedon glass which is not transparent but is translucent. Therefore, by theterm transparent which I use in the specification and claims, I intendto cover both transparent and translucent.

Having thus described my invention, what I claim is:

1. The method of etching glassware which comprises applying upon a glassarticle an acid resist interrupted by an area of selected design to forma silhouette and applying to such area an acid solution of 2 parts ofwater and 1 part 80% soluton of hydrofluoric acd for a period rangingfrom to 60 minutes.

2. The method of etching glassware which comprises applying upon a glassarticle an acid resist interrupted by an area of selected design, andapplying to such area an acid solution of 2 parts 45 of water and 1 part80% solution of hydrofluoric acid for a period ranging from 45 to 60minutes.

3. The method of etching glassware which comprises applying upon a glassarticle an acid resist interrupted by an area. of selected design toform a silhouette, dipping said article in a bath of an acid solutioncomprising 2 parts of water and 1 part 80% solution of hydrofluoric acidand allowing the article to remain therein for a period ranging from 45to 60 minutes so as to produce a rough etched surface of differentelevations, the portions toward the center of the silhouette designhaving the lowest elevations.

RONALD L. WOOLES.

